Relevance: GS-3 (Science & Technology, Defense & Internal Security) | Source: The Indian Express

1. What is the Core News?

India has officially mastered a highly complex defense technology.

• The Achievement: The Defence Research and Development Organisation (DRDO) successfully ran a full-scale Scramjet engine for a record 20 minutes (1,200 seconds).
• The Administrative Significance: Sustaining this engine for so long proves that India can now power long-range hypersonic cruise missiles. This places India in an elite global club alongside only the US, Russia, and China.

2. The Science Made Simple 

To understand this breakthrough, an administrator must know the basic vocabulary of high-speed flight:

• Hypersonic Speed: Flying at more than 5 times the speed of sound (Mach 5).
• Air-Breathing Engines: Normal space rockets are heavy because they must carry both fuel and heavy oxygen tanks to burn that fuel. “Air-breathing” engines are smarter—they suck in oxygen directly from the atmosphere as they fly. This makes the missile much lighter, allowing it to carry heavier explosives (warheads).
• Ramjet vs. Scramjet:
  • Ramjet: It sucks in fast-moving air but has to slow it down (below the speed of sound) inside the engine to ignite the fuel. It stops working well once you cross Mach 5.
  • Scramjet (Supersonic Combustion Ramjet): The upgraded version. It can ignite fuel while the air inside is still rushing at super-fast (supersonic) speeds. Scientists compare this to the near-impossible task of “lighting a matchstick in a hurricane.”

3. How Did DRDO Do It?

Flying at Mach 5 creates extreme physical challenges. DRDO succeeded by inventing three local solutions:

• Flame Stabilisation: They designed a system that successfully holds a continuous fire inside the engine, even when wind is blasting through at 1.5 km per second.
• Endothermic Fuel (Cooling Fuel): They created a special liquid fuel that does double duty. It catches fire easily, but before burning, it absorbs massive amounts of heat. This acts as a built-in coolant to save the engine from melting.
• Thermal Barrier Coating (Heat Shield): Flying at Mach 5 creates air friction so hot that it melts solid steel. DRDO developed an advanced ceramic “heat shield” paint that protects the missile’s body from burning up.

4. Strategic Value for India

For India’s national security, hypersonic missiles completely change the rules of modern warfare:

• Defeating Air Defenses: Traditional ballistic missiles fly high in a predictable arch, making them easy to track. Hypersonic cruise missiles fly low, super-fast, and can change direction randomly. They can easily dodge and defeat the world’s best missile defense systems.
• Rapid Strike: India can now hit enemy targets hundreds of kilometers away in a matter of minutes, giving the enemy zero time to detect or react.
• True Atmanirbharta (Self-Reliance): Instead of importing future-tech, India is building its own strategic deterrence, anchoring itself as a leader in the 21st-century arms race.

UPSC Value Box 

• Mach Number: The speed of an object compared to the speed of sound. Mach 1 is the speed of sound. Mach 5+ is Hypersonic.
• DRDL (Defence Research and Development Laboratory): The premier Hyderabad-based DRDO lab that designed this engine.
• Strategic Deterrence: Having military capabilities so advanced and destructive that an enemy is too scared to even attempt an attack.

Q.2. With reference to missile technology and engine types, consider the following statements:

1. Hypersonic speed is defined as a speed that is strictly between Mach 1 and Mach 3.
2. An air-breathing engine draws oxygen directly from the atmosphere, eliminating the need to carry heavy oxidizer tanks.
3. In a Scramjet engine, the airflow through the engine remains at supersonic speeds during fuel combustion.

Which of the statements given above is/are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3

Correct Answer: (b)